Triplet pregnancy complicated by a gradual decline in antithrombin-III activity and HELLP syndrome: a case report.

We prospectively evaluated the antenatal changes in antithrombin-III (AT-III) activity and liver enzymes in a woman with a triplet pregnancy. A gradual decline in AT-III activity occurred in the absence of clinical signs of preeclampsia and preceded the onset of the typical HELLP syndrome in this patient. Monitoring of AT-III activity might help to avoid the development of severe HELLP syndrome.